Improving the Efficiency and Turnover of a Domestic Wastewater Treatment Plant Using Coagulation–Flocculation

ABSTRACT This study aimed to improve the performance efficiency of a domestic wastewater treatment plant in Prasanthi Nilayam, India. Coagulation–flocculation was identified as an alternative to the underperforming sequential batch reactor process, based on the characteristics of the influent wastewater. The study analysed the effects of coagulant dose, wastewater pH and fast‐stirring speed on the efficiency of treatment using Ecoclean‐2300, a commercially available, proprietary herbal‐based coagulant–disinfectant. The effects of coagulant dose, wastewater pH and fast‐stirring speed on turbidity and total suspended solids (TSS) reduction were analysed using the Box Behnken design of response surface methodology, which yielded a quadratic model describing the interactions among the factors. For a wastewater pH of 7.5, the optimal coagulant dose was 1 μL/L, with a fast‐stirring speed of 165 rpm, meeting regulatory limits for non‐potable applications. These findings could triple the output of the treatment plant, offering a scalable framework for optimising wastewater treatment in resource‐limited settings globally.